We have identified new biomarkers of inflammation that both reveal the severity of COVID-19 and set it apart from severe influenza. Many inflammatory cytokines were found in greater numbers in severe COVID-19 and that these levels generally indicate severe disease. We identified patterns within the data that were the most clearly linked to severe cases of COVID-19; two cytokines in particular, IL-6 (interleukin 6) and GM-CSF (granulocyte-macrophage colony stimulating factor) play central roles. With more research, we can see if GM-CSF could be used as a marker in early disease to identify those at risk of going on to develop more severe symptoms.